Inhibitory effects of angiotensin-(1–7) on the nerve stimulation-induced release of norepinephrine and neuropeptide Y from the mesenteric arterial bed

Autor: Heather Macarthur, Mirnela Byku, Thomas C. Westfall
Rok vydání: 2010
Předmět:
Male
medicine.medical_specialty
Sympathetic nervous system
Sympathetic Nervous System
Pyridines
Physiology
Stimulation
Rats
Inbred WKY
Receptor
Angiotensin
Type 2
Synaptic Transmission
Norepinephrine (medication)
Norepinephrine
chemistry.chemical_compound
Rats
Inbred SHR
Physiology (medical)
Internal medicine
medicine
Animals
Neuropeptide Y
Neurotransmitter
Mesenteric arteries
Antihypertensive Agents
Dose-Response Relationship
Drug
Imidazoles
Articles
musculoskeletal system
Neuropeptide Y receptor
Electric Stimulation
Peptide Fragments
Mesenteric Arteries
Rats
Disease Models
Animal
Autonomic nervous system
NG-Nitroarginine Methyl Ester
medicine.anatomical_structure
Endocrinology
chemistry
Hypertension
cardiovascular system
Catecholamine
Angiotensin I
Cardiology and Cardiovascular Medicine
hormones
hormone substitutes
and hormone antagonists
medicine.drug
Zdroj: American Journal of Physiology-Heart and Circulatory Physiology. 298:H457-H465
ISSN: 1522-1539
0363-6135
DOI: 10.1152/ajpheart.00400.2009
Popis: Neuropeptide Y (NPY) is a cotransmitter with norepinephrine (NE) and ATP in sympathetic nerves. There is evidence for increased activity of the sympathetic nervous system and the renin-angiotensin system (RAS), as well as a role for NPY in the development of hypertension in experimental animal models and in humans. Angiotensin II (ANG II) is known to facilitate sympathetic neurotransmission, an effect greater in spontaneously hypertensive rats (SHR) than normotensive Wistar-Kyoto (WKY) rats. A newly discovered product of the RAS is angiotensin-(1–7) [ANG-(1–7)]. There is evidence suggesting that ANG-(1–7) opposes the actions of ANG II, resulting in hypotensive effects. The objective of this study was to investigate the role of ANG-(1–7) on the nerve-stimulated overflow of NE and NPY from the mesenteric arterial bed of SHR and the mechanisms involved in mediating any effects produced. ANG-(1–7) (0.001, 0.01, 0.1 μM) decreased nerve-stimulated NE and NPY overflow, as well as perfusion pressure in preparations obtained from SHR. This effect was greater in preparations of SHR than WKY controls. In addition, ANG-(1–7) decreased NE overflow to a greater extent than NPY overflow. Administration of the Mas receptor antagonist, d-Ala7 ANG-(1–7), attenuated the decrease in both NE and NPY overflow due to ANG-(1–7) administration. However, the angiotensin type 2 receptor antagonist, PD-123391, attenuated the effect of ANG-(1–7) on NE overflow without affecting the decrease in NPY overflow. Moreover, in the presence of NG-nitro-l-arginine methyl ester, ANG-(1–7) decreased NPY overflow, but not NE overflow. ANG-(1–7) decreases the nerve-stimulated overflow of NE and NPY in preparations of SHR, whereas ANG II enhances it. Therefore, ANG-(1–7) may counteract the effects of ANG II by acting on ANG type 2 and Mas receptors.
Databáze: OpenAIRE
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